Air Conditioner Service Form

Use at least one of the following methods to verify required cfm for outdoor unit operation. Using 2 methods is better then using just 1, just in case something does not look correct. The goal is 350 cfm per a ton.

Go into the service menu by pressing and holding the service hat icon until it turns green. Then select the installation option, then select the blower assessment test, start the test, it will take about 3 mins to complete, once the test is complete record the information below.

Record the static pressure with a manometer. Measure the return and the supply separately and then add together to get the total static. Forget the + and – and just add the numbers together. Example +.5 measured in the supply and -.3 measured in the return = .8 in wc Total static. Reminder this is a Blower, not a sucker.

Place the unit in the heating mode and turn off all other natural gas appliances. Go to the gas meter and time how many seconds it takes for the furnace to consume 1 cubic foot of gas. See gas furnace videos for instructions on how to do this. And then measure the temperature spilt of the gas furnace at the furnace.

Verify input BTU of furnace: 3600 sec in an hour / Seconds per a cubic foot of gas the furnace consumed = cubic feet per an hour consumed X AVG BTU content of 1050 = give us the input BTU’s of the furnace. Make sure it matches the name plate of the furnace. If not adjust gas pressure. Then take the output rating and / temperature split / 1.08 = CFM. Example 3600 secs / 62 sec to consumer 1 cubic foot = 58 cubic feet of gas consumed X 1050 = 60,900 Btu’s Input, Nameplate say 60k input, we are good as long as within 2%. Then look at output rating of the furnace 54kbtu. Take the 54,000 Btu output / your temperature split(52F measured) / 1.08 = 961 CFM. Again you can watch the video that is located in the gas furnace troubleshooting section.